But You Know All That
by magentacr
Summary: Mycroft knows everything.


_AN: Yeah, this is me taking a break from writing *rolls eyes at herself* I just can't help myself apparently._

 _No copyright infringement intended, I borrow the characters purely for enjoyment not money._

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Sherlock hated funerals. He avoided them as far as he could, but though he knew how much he would hate this funeral in particular, he couldn't miss it. It was Mary's funeral. He hated it on principle that it shouldn't be happening, that he should have protected her better, but he also hated it for its dull predictability. He almost wasn't sure why he had come; not for himself, he didn't believe there was any use in saying goodbye to someone

too dead to hear you. Not for John either, his friend was still stubbornly refusing to make eye-contact with him, the angry clenching of his jaw confirming that he knew of Sherlock's presence and was unhappy with it. And as for the ceremony itself, he could just as easily picture it in his mind's eye without having to be here, from the lack of guests (even less than the wedding) to the particular flowers on the coffin. The priest's speech was bound to be a generic, dry recitation of facts about Mary's life that were probably not factual at all, and John's eulogy would be short and to the point, barely above a whisper as he struggled with emotion and shortly gave up. He'd put money on it, just to make the funeral more interesting, if he wasn't aware how wildly inappropriate it would be.

But then he saw something that did surprise him. Standing just in the shadow of the doorway, as the pall bearers brought the coffin in, was a figure. A familiar, tall, balding, sharp-nosed figure, declining the attendant's offer to step in, in favour of remaining outside. Before the door could close, Sherlock jumped to his feet and slipped out.

"What are you doing here, Mycroft? You never attend these things." He asked, almost accusingly.

"I could say the same of you. Perhaps that's why we're both _out here_ , rather than _in there_." Mycroft answered knowingly. He drew a packet of cigarettes out of his right breast pocket, and took one for himself before offering the box to Sherlock, who had already beaten him to it and was lighting his own. They smoked in silence for a few moments, each lost in their own thoughts, until a particular one struck Sherlock.

"Lady Smallwood said _you_ wound up AGRA and the other freelancers…"

"Sherlock." Mycroft cut him off sternly "The case is over, you solved it. Going back over the details is not going to change anything. It won't bring her back."

"You don't like loose ends, so you would have been very thorough going over the files." Sherlock continued as if he hadn't been interrupted "And you never forget a face, especially not one who might be hired to kill you one day. You _did_ know who she was. Right from the start, when she and John first met."

"So I did." Mycroft confessed, with an unapologetic smile. There was a pause while they both took drags of their cigarettes, and Sherlock basked in the knowledge he was right, before snorting a laugh.

"Some watchdog you are. You were supposed to be making sure he didn't get into any trouble while I was gone and you let him fall in love with an assassin."

"Are you suggesting I should have driven her away? That it would have been better for John never to have known her at all than love her and lose her?"

Sherlock paused to think about it for a second, but it didn't take him much longer than that to reach a conclusion.

"No. No, even though she's gone, I think John's life was all the better for having had her in it."

Mycroft didn't voice his agreement, but gave a small nod in acknowledgement.

"I was concerned, of course, when they first met. I did some very discrete digging and kept as close an eye on the situation I could - which was not easy with a woman like her, I must add. But she hadn't taken any work of that kind since the dissolution of her team, and her interest in John seemed quite genuine, so I allowed it to continue. To be honest, I was for a long time under the false assumption that she had told him about her past life and that that was the draw for him, after how he was with you."

"What do you mean, how he was with me?"

There was nothing in the world Sherlock found more irritating than his brother's I-know-something-you-don't face. It was a face he would very much like to punch one of these days. Perhaps not today though.

"So is there anything else about Mary's past I should know? Anything that could still threaten the lives of her remaining family? I need to know if I'm going to try and keep my promise to protect them."

"Nothing that I am aware of." Mycroft shrugged.

"Well… you don't know everything I suppose." Sherlock sighed, tapping the growing ash off the end of his cigarette and turning away, his mind already whirring and planning how he could discover more, not wanting to leave any stone unturned that might one day come back to bite them.

"I know she shot you." Mycroft called back to him. Sherlock's head tilted back in surprise, though when he turned to face his brother his face was the picture of innocent ignorance. That look had never fooled Mycroft, even when they were children, and he wasn't about to let it now.

"I admit I was a little confused at first when I heard what had happened to you, that whomever had attacked you in Magnussen's office had done everything else so expertly, and yet failed to kill either you or Magnussen. But then when John Watson decided to move back in with you rather than his dear wife, it all became very clear. She had just the kind of secrets he could exploit, she had motive to want him dead, but also motive to keep you alive. It was obvious really."

"So you knew." Sherlock conceded, knowing there was no further point in denying it. "And yet you didn't turn her in? Or… I don't know, try to have her assassinated? Or did you?" Sherlock looked speculative for a second.

"You know I didn't. And you know why." Mycroft gave him a meaningful look, but expounded on his point anyway. "It's another reason why she was so obviously the culprit. You had been shot in the front, you definitely saw your attacker, and yet when questioned by the police you claimed ' _you didn't get a good enough look to see anything to identify your attacker by.'_ "

"She was wearing a balaclava."

"She could have been wearing a full face prosthesis and both you and I know you still could have noticed something to identify her, or anyone else by." Mycroft snapped. "You were protecting her, and therefore I had to view her as under your protection."

"So you did nothing?" Sherlock asked doubtfully.

"I may have sent her a little message to let her know I knew."

"And imply some kind of threat, no doubt. How did she take it?"

"Like a Watson." Mycroft stated, to Sherlock's amusement. "Anyway, if that's all you want to ask me, you should probably head back inside. John will be starting his eulogy any moment, and he'll need you."

"I doubt that." Sherlock scoffed bitterly, "Didn't you see his face? He clearly doesn't want me here. Save perhaps for in the coffin in place of his wife."

"I wouldn't be so sure. Besides, one day you will come to understand that just because someone doesn't want you, doesn't mean they don't need you." He gave Sherlock another penetratingly meaningful look, stubbed out his cigarette in the provided receptacle and turned and walked away. Sherlock took one last drag of his before doing likewise and slipping back into the crematorium, just in time to see John taking his place at the rostrum.

He got two lines into his speech before meeting Sherlock's eyes, choking out some final words, and marching away like the soldier he was.


End file.
